Need to build a GPS unit for my next project. Searched on line and found lots of information about GPS tracker. A good one of them is Trimble Trimtrac Locator. It’s an affordable GPS tracker for common people like the one used by spies to track the vehicle of VIPs. It combines a GPS receiver and GSM unit into one single chip. Perfect for my case.
But I found an even cheaper solution that doesn’t come with a wireless transmission unit. This requires people to build it by themselves. All they need is a GPS receiver (e.g. EM-406A), a SD Datalogger which parses the data from GPS receiver and saves it into a SD card, a SD card, LiPo batteries and some cables and connectors. I believe it’s easy to build and very cheap (under $150). Even better for my case. You can check the good GPS buying guide from SparkFun.